1. Field of the Invention
The present invention relates to a device and method for centering truck wheels on a truck hub.
2. Description of the Prior Art
Concentric mounting of wheels on vehicle hubs have long been a concern in the marketplace. Much attention has been given to the concentric mounting of automotive wheels on the automotive hubs so as to minimize vibration of the wheels in operation and add to the comfort of the passenger. One such effort led to the proposal of a wheel having a recessed well configured with a center bore surrounded by lug bores and including a bushing device having a flat plate for overlying the lug bores and itself formed with matching bores, such plate being configured centrally with an integral cylindrical bushing to be received in the wheel bore to mate with the wheel hub. A separate flat plate cover was proposed for positioning in covering relationship over such bushing plate to be held in position by separate mounting screws. A device of this type is shown in U.S. Pat. No. 5,362,134 to Carmona. Devices of this type, while satisfactory for some automobile wheel applications, do not lend themselves to use on truck wheels having projecting grease hubs which themselves must be covered. Arrangements for facilitating hub centric mounting of automobile wheels does not generally lend itself to truck wheels since the physical mounting characteristics thereof are different. It is the problem of eccentric mounting of truck wheels to which this invention is directed.
Truck hubs are often formed with a hub arrangement having an axially projecting, cylindrical oil hub of about three to five inches in diameter and over which is received a hub cap positioned in covering relationship. Truck wheels are typically provided with a lug hole pattern of five, six or eight lugs arranged on a hole pattern concentric with a wheel center bore. The lugs pass through lug holes in such wheels concentric about a center bore through which the hub itself projects. The hub may be formed with a raised centering shoulder that might be matched with the bore of a particular wheel. However, the diameter of the center bores of various wheels often vary. Consequently, when wheels are mounted on hubs where the diameter of the bore does not correspond with the hub diameter or centering shoulder, the wheel might end up mounted slightly eccentric on the hub thus resulting in vibration when the truck is operated at certain speeds.
Efforts over the years to solve the problems associated with eccentric wheel mounting has included proposals that closed metal rings or plastic bushings be cemented to the wheel hub so as to reduce place between the hubs and axles. This solution is labor intensive and requires some degree of skill in achieving the appropriate setting.
Other methods proposed include the interpositioning between the axle and wheel of first and second rings of different diameters and then keying one to the axle and welding the rings together. Again, this is a labor intensive and high skill process.
It has also been proposed to provide a hub according to a maximum diameter of axles to be equipped with a ring to be interplaced between the hub and the wheel so as to occupy the annulus between the wheel and hub. A device of this type is shown in German Patent No. 3233807 filed Sep. 11, 1982. A drawback to this approach is that it employs an elastic ring which is relatively narrow and can give rise to instability.
Other efforts have led to a proposal that the inner wall of the wheel bore be configured with a land for receipt of selected ones of stepped bushings having various internal diameters and adapted to be locked in place by means of a split lock ring. A device of this type is shown in U.S. Pat. No. 5,518,302 to Bemoni. Devices of this type, while effective to improve concentricity, suffer the shortcoming that they are expensive to manufacture, difficult to mount and leave the axial outer end thereof exposed.
Various types of hub caps have been proposed for covering a truck wheel hub. One such hub cap is known as the push through cap. It is in the form of a cup shaped cap for fitting over the hub and is typically formed at its axially inner extremity with an outwardly turned flange to be captured under the chamfer around the center bore of the wheel.
Other truck hub caps have been proposed which fit telescopically over the truck hub but have adhesive material interposed between the cap wall and hub. A device of this type is shown in U.S. Pat. No. 5,366,279 to Polka. However, such caps are specific to particular diameters of hubs and do not have broad application for establishing concentricity of wheels relative to hubs.